The present invention relates to an elevated frog for a railway switch panel. A railway frog is employed where one track crosses another. For example, in a turnout, a switch will selectively switch a train from a main track to a turnout track. As the turnout track progresses in a curve from the switch, one of the rails must cross a rail of the main track. The junction assembly at such crossing is called a frog.
Typically, railroad turnout frogs are the highest maintenance item in a turnout. The flangeway or gap in the frog is necessary to allow the wheels of a train to cross a rail. When the wheels cross the gap they generate impacts that adversely affect the frog, wheels, and the track structure. Although each of the foregoing designs is workable, an improved design that further reduces the railroad maintenance would be desirable.
In providing for rail switching, it is important to accommodate several aspects relating to the main line running and turn out rail line.
In order to allow the train car wheel set to cross onto the turnout rail line, it must be raised to a height to allow it to cross the main running rail, and then returned to the base running height.
Typically this is accomplished by using frog casting disposed on either side of the main line rail on the turnout side. These castings are designed to lift the wheel, direct it through the transition zone over the turn-out side main line rail, and capture the wheel, allowing it to relax to the established rail elevation. For these purposes, the dual frogs are specially cast and custom machined to provide the required shaping, such as that to provide the required ramping and channeling for support and capture of the wheel tread and flange, to be able to firmly and accurately provide mechanical action under high strain and impact conditions.
It is also typical that frog designs accommodate canted main running rails used in higher speed track sections, such as those that may accommodate mainline speeds of 50-60 mph.
It is advantageous to be able to provide this mechanical action with reduced expense and effort associated with the production of relatively expensive multiple castings that require custom machining that are customary in the industry. In this regard, frog castings typically incorporate ramping in the design of the main body casting that require rather complex post-casting machining, and it is beneficial to reduce or eliminate complex ramping within the body of the casting.
It is also best to provide a uniform, unbroken wheel path that distributes load and reduces wheel and frog wear, such as may be accomplished by providing a horizontal wheel path that is not interrupted by wheel-to-rail interface.
Typically dual frog casting systems must incorporate all of the required ramping with the length of the casting, which requires relatively larger castings to distribute the ramping length to reduce inertial bounce as the wheel sets pass over the main line rail. This makes typical frog casting systems relatively large and expensive. Accordingly, it would be beneficial to reduce the overall casting size, and thereby reduce the initial cost of frog production while at the same time reducing the cost of attendant repair and maintenance.
It is also beneficial to provide a crossing system that may be made and installed simply, while also being adapted for prefabrication and installation, and one that is relatively easy to assemble and repair. In this regard, it is desirable to eliminate multiple castings, make their production easier and less expensive, and provide frog panels that are adapted to reduce overall track and crossing wear associated with long term use, and that accommodate changes in wheel geometry as wheel degradation occurs over the wheel's operational life cycle.
The embodiments of the invention described herein addresses the shortcomings of the prior art.